textproduct: Quad Cities

KEY MESSAGES

- Occasional light rain is possible in areas along and west of the Mississippi River through early Sunday morning, with mostly dry conditions moving in later Sunday into Monday.

- Another active weather pattern will set up in the middle of the upcoming work week, bringing the potential for rounds of heavy rainfall and thunderstorms to the area.

- Temperatures will remain near to slightly above seasonal norms through the next week.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 200 PM CDT Sat Sep 26 2026

Patchy light rain across southern and western portions of the outlook area will continue to diminish through the mid/late afternoon as forcing aloft wanes. Temperatures will reach the low 60s to low 70s for highs (west to east) then fall back into the 50s tonight. A 500mb vorticity max, currently over northeast Kansas per the SPC mesoanalysis, will shift northeastward tonight and bring a round of scattered showers/patchy light rain to portions of the outlook area late into early Sunday AM. Again, western and southern counties (mostly west and south of the Quad Cities) have the highest chances for some rain (30-50%). The mid-level wave will be entering into a zone of upper-level confluence which will force a more southeastward trajectory into Sunday, leading to largely dry conditions from late Sunday AM through the evening. Highs on Sunday will be comfortable, reaching the upper 60s to low 70s.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 200 PM CDT Sat Sep 26 2026

Going into Monday, we will continue to see influence from the building high pressure over the Great Lakes Region. A greater push of dry air will work into the area, allowing for the potential for more breaks in the clouds. This will be a welcome sight for those that have been socked in by clouds and light precipitation this weekend. Overall, we are expecting to remain dry through Monday, with temperatures warming to near 70 throughout.

This period of dryness will come to an end mid-week as a larger system builds in sometime around Tuesday/Wednesday. A longer wave trough, with models showing a strong tropical connection to the systems from the eastern Pacific and the Gulf, should translate through the area, although the exact onset/ending time of associated precipitation remains uncertain. This is pretty clearly shown from the LREF ensemble cluster analysis, which shows various depictions of the longer wave trough aloft. Some show a large progressive trough sweeping across the central CONUS, while some show a slower cut-off low with multiple rounds of rain mid to late week. However, there remains a strong signal for abundant moisture with this system given the tropical connection, with Pwat values progged around 1.6 to 2 inches, which is quite high for late September. In fact, these values would be in excess of the 99th percentile for Pwats per the NAEFS climatological percentiles. NBM exceedance probabilities for one inch or more of rain for Tuesday night and Wednesday are around 40-60%, which is actually a pretty decent signal given we're talking several days out. Despite the uncertainty on the exact duration and magnitude of rainfall amounts, this signal appears supportive of heavy rainfall and perhaps a flash flooding threat, given wet antecedent conditions. So, this mid-week system bears watching. With this, WPC has much of our area in a Day 5 Slight Risk (level 2 of 4) in their latest excessive rainfall outlooks.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 647 PM CDT Sat Sep 26 2026

VFR conditions are largely expected for the latest TAF set. Latest observed sounding data from our office in Davenport shows a stout layer of dry air below 6kft, which is helping to maintain dry conditions and VFR ceilings. Another wave of light rain showers (20-40% chance) is possible late tonight into early Sunday AM as a weak system moves in from the west. At this time, CID and BRL appear most likely to be the only TAF sites that could see rain, but confidence remains low on impacts to visibility due to the abundant dry air. East-southeast winds will remain light through the period.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.